(19)
(11) EP 1 085 456 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
03.03.2004 Bulletin 2004/10

(43) Date of publication A2:
21.03.2001 Bulletin 2001/12

(21) Application number: 00307697.3

(22) Date of filing: 07.09.2000
(51) International Patent Classification (IPC)7: G06K 9/34, G06K 9/32
(84) Designated Contracting States:
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
Designated Extension States:
AL LT LV MK RO SI

(30) Priority: 15.09.1999 US 396952

(71) Applicant: SIEMENS CORPORATE RESEARCH, INC.
Princeton, New Jersey 08540 (US)

(72) Inventors:
  • Tyan, Jenn-kwei
    Princeton, NJ 08540 (US)
  • Neubauer, Claus
    Monmouth Junction, NJ 08852 (US)

(74) Representative: O'Connell, David Christopher 
Haseltine Lake Imperial House 15-19 Kingsway
London WC2B 6UD
London WC2B 6UD (GB)

   


(54) Character segmentation method for vehicle license plate recognition


(57) A method for segmenting and recognizing license plates, in accordance with the present invention includes capturing an image of a license plate (100) and preprocessing the image to prepare the image for segmentation and recognition (110). Forward splitting regions of the license plate image into suspected characters regions, the suspected character regions are recognized in the license plate image and a confidence score is provided based on a probability of a correct match (114). If the suspected characters have a confidence score below a threshold value, backward merging is employed which merges adjacent suspected character regions (116). The backward merged suspected character regions in the license plate are recognized. If the backward merged suspected character regions have a confidence score below the threshold value, the backward merging and recognizing steps are repeated to improve the confidence score.






Search report